RF measurement of T18 after High power test
Jiaru Shi27.07.2011
Before high power testing
after high power testing
CERN built T18
Faya Wang @ SLAC
Faya Wang @ SLAC
After high power testingBefore high power testing
Standing wave patternReflection before last regular cell
0.02
0.04
0.06
30
210
60
240
90
270
120
300
150
330
180 0
after
before
Detuning of cells(difference of required tuning)
0 5 10 15 20-3
-2
-1
0
1
2
3
4
5x 10
6
number of cells
df a
fter
hig
h po
wer
tes
ting
(Hz)
Not sure for input matching cell
Amplitude Measurement of T18-SLAC #1 Before and After High Power Test
11421.7 MHz at 21.32°C, N2 Before high Power test
11421.87 MHz at 20.4°C, N2 After high power test
Juwen Wang @ SLAC
1350 hours
11421.7 MHz at 21.32°C, N2 ore high Power test
11421.87 MHz at 20.4°C, N2 After high power test
Phase Measurement of T18-SLAC #1 Before and After High Power Test
Juwen Wang @ SLAC
Amplitude Measurement of TD18-SLAC Before and After High Power Test
11424.5 MHz at 21.46°C, N2 Before high Power test
11424.56 MHz at 21.1°C, N2 After high power test
Juwen Wang @ SLAC
Phase Measurement of TD18-SLAC Before and After High Power Test
16.5°
11424.5 MHz at 21.46°C, N2 ore high Power test
11424.56 MHz at 21.1°C, N2 After high power test
Select bead pulling frequencies based on the same measurement condition for both before and after high power test
Juwen Wang @ SLAC
Amplitude Measurement of T18-SLAC #1 Before and After High Power Test
11424.1 MHz at 20.02°C, N2 Before high Power test
11424.15 MHz at 20.4°C, N2 After high power test
T24Juwen Wang @ SLAC
Phase Measurement of T24-SLAC Before and After 800 Hours High Power Test
Select bead pulling frequencies based on the measurement condition to get 2π/3 phase advance for both before and after high power test
6º
11424.1 MHz at 21.1°C, N2 After high Power test
11424.1 MHz at 21.2°C, N2 Before high power test
Juwen Wang @ SLAC
T18 SLAC N1 TD18 SLAC T24 SLAC T18 CERN N2
Measured at SLAC SLAC SLAC CERN
Output matching
Standing Wave(SWR)
1.06 1.2 1.05 1.1
(reflection) 0.03, -30dB 0.1,-20dB 0.025, -32dB 0.05, -26dB
Estimate df if only one cell detuned
2MHz 7MHz 2.5MHz 3MHz
from standing wave pattern
N-1 cell-F
N-1 cell-F
Output cell+F
N-1 cell -F
Regular cells
Total phase shift -16 deg +6 deg
~df +1 MHz -0.3 MHz
TD18 Chamfer100 um -1MHz
Chamfer TD18
20.00 40.00 60.00 80.00 100.00r_chamfer [um]
-0.13
0.00
0.13
0.25
0.38
0.50
0.63
0.75
(re
(Mo
de
(1))
-11
42
5M
Hz)
/1M
Hz
Ansoft LLC f0XY Plot 2 ANSOFT
Curve Info
(re(Mode(1))-11425MHz)/1MHzSetup1 : LastAdaptive
T18 chamfer100 um -0.5MHz
10.00 30.00 50.00 70.00 90.00r_chamfer [um]
0.05
0.15
0.25
0.35
0.45
0.50
(re
(Mo
de
(1))
-11
42
4M
Hz)
/1M
Hz
Ansoft LLC cell_1XY Plot 1 ANSOFT
Curve Info
(re(Mode(1))-11424MHz)/1MHzSetup1 : LastAdaptive
TD18 Iris ellipse aspect ratio 1.1 to 1.2frequency + 8.2MHz
1.100 1.120 1.140 1.160 1.180 1.200e
-6.00
-4.75
-3.50
-2.25
-1.00
0.25
1.50
2.75
(re
(Mo
de
(1))
-11
42
4M
Hz)
/1M
Hz
Ansoft LLC f0XY Plot 2 ANSOFT
Curve Info
(re(Mode(1))-11424MHz)/1MHzSetup1 : LastAdaptive
0 0.5 1
3
3.5
4
4.5
z (mm)
r (m
m)
1.1
1.2
aspect ratio
+1MHz ~ removing 0.12mm3 copper at the iris